Sinuses scan in hospitals are mainly used for diagnosing injury, deformity, malignant tumor and inflammation. A doctor firstly scans a scout image so as to localize the position of sinuses from a frontal sinus to a nose (including external nose, nasal cavity). Currently the above positioning is a manual operation completed by the doctor. The doctor needs to manually click or drag a mouse to change the start position and end position of the final axial scanning on the scout image. There exist a lot of defects in the manual positioning of sinuses scan.
On the other hand, orbit scan in the hospitals are mainly used for the diagnosis of orbital structural diseases and orbital components, injuries and foreign objects. The doctor also needs to scan a scout image, so as to position the orbit from 0.5 cm below the eyehole to 0.5 cm above the eyehole through manual operations. The doctor needs to manually click or drag a mouse to change the start position and end position of the final axial scanning on the scout image. There exist a lot of defects in the manual positioning of orbit scan.
FIG. 1 shows in more details a flow chart 100 of manually positioning a scout image in the prior art. At starting Step 102 of the flow, a patient such as a subject is positioned at a position convenient for being scanned, e.g., the patient is usually transported and positioned at a stand of a scanning system. Then, at Step 104, scout scanning is conducted to the patient, so as to obtain a scout image. As a non-restrictive example of the above step, the scout image can be obtained by adopting the following manner: an operation console in a X-ray CT apparatus is utilized to control a scanning frame of the X-ray CT apparatus, such that a X-ray tube in the scanning frame emits X-rays (the X-rays, e.g., are shaped through pores to be represented as fan-shaped beams, cone-shaped beams, etc.); the shaped X-rays are transmitted towards the patient positioned on the stand, penetrate through the patient and are applied to a X-ray detector (the detector can be X-ray detecting elements having a plurality of two dimensional settings in the propagation direction (channel direction) and thickness direction (column direction) of the fan-shaped X-ray beams) of the X-ray CT apparatus located on another side of the stand; finally, a data acquisition segment of the X-ray CT apparatus acquires detected data from various X-ray detecting elements, take the data as projection data, and obtains a “scout image” based on the projection data. Incidentally, the image per se indicating the scout image and the image data bearing the image all can be called scout image in the whole text, without any distinction.
Next, at Step 106, a user (e.g., a doctor) manually adjusts and positions the scout image generated at Step 104 based on his/her own experiences and vision. Then, at Step 108, he/she manually sets a final axial scanning scope on the scout image, e.g., manually clicking or dragging a mouse to set, change, adjust the start position and end position of the axial scanning. In other situations, the user can also make changes and adjustments to the scanning scope (e.g., the start position and end position) through keyboard input, voice input, or other known ways. Finally, at Step 110, the user confirms the adjusted scout image and scanning scope by clicking a confirmation button on a graphical user interface (not shown), and performs the axial scanning (e.g., CT tomography scan) based on the scanning scope, so as to form an axial scanning image for further treatment or diagnosis.
The currently known defects existing in the above manual positioning 100 of scout image (e.g., sinuses scan and orbit scan) include, but are not limited to: the manual positioning 100 takes time and efforts; it mainly relies on the doctor's experiences and vision; and in the case that the operator is not familiar enough with it, the manual positioning 100 may be inaccurate, and thus is unable to execute the anticipated axial scanning. Further, since the eyes of the subject are usually sensitive to X-rays and it is hoped that the least radiation dose is incident into the eyes, it is extraordinarily desired in the art that orbital scanning is automatically positioned with high precision.
In this field, there are already some ways and means, for positioning scanning images.
For example, a Chinese patent application (CN 101234028A), published on Aug. 6, 2008, presents a method of generating a CT scanning scout image in a SPECT-CT based multiple mode scanning system. The method utilizes image information (e.g., loid) of the SPECT side to fill in the scan option of a scan protocol of the CT side, and utilizes the filled scan protocol to read out SPECT image at the CT side to act as scout image at the CT side. However, the above method focuses on the compensation of SPECT mode to CT mode, thereby realizing less dose and higher availability, but fails to solve the technical problem of automatically positioning scout image which is anticipated by this disclosure to be solved.
As another example, a Chinese patent application (CN 102365655A), published on Feb. 29, 2012, presents an image matching device based on an ICP (Iterative Closest Point) method, in which a solution is converged to an optimal solution while avoiding the ICP method to reach a local solution (i.e., only ensuring the error function to reach the local minimal value). However, this patent application does not relate to the apparatus of automatically positioning scout image as depicted by the present disclosure.
As a further example, a Chinese patent application (CN 102342847A), published on Feb. 8, 2012, presents realizing a scan range in which unnecessary exposure to a subject 8 is reduced, by simultaneously adjusting a tilt angle of a tilt image to be reconstructed and a tilt image reconstruction range (via a tilt image reconstruction range input reception unit 602) and adjusting a scan range for a non-tilt scan (via a non-tilt scan range input unit 603). However, adjustments to the tilt image reconstruction range and the scan range for a non-tilt scan still need to manually conducted, so the problem anticipated by the present disclosure to be solved cannot be solved by the above application.
In summary, in the prior art, there exists no automatic positioning apparatus for scout image scan (e.g., sinuses scan and orbit scan as mentioned above) with high precision. Therefore, an apparatus for efficiently automatically positioning scout scan such as sinuses scan and orbit scan, is desired.